Class: HTMLPipeline::NodeFilter::AssetProxyFilter

Inherits:
HTMLPipeline::NodeFilter show all
Defined in:
lib/html_pipeline/node_filter/asset_proxy_filter.rb

Overview

Proxy images/assets to another server, such as [cactus/go-camo](github.com/cactus/go-camo#). Reduces mixed content warnings as well as hiding the customer’s IP address when requesting images. Copies the original img ‘src` to `data-canonical-src` then replaces the `src` with a new url to the proxy server.

Based on github.com/gjtorikian/html-pipeline/blob/v2.14.3/lib/html/pipeline/camo_filter.rb

Constant Summary collapse

SELECTOR = 
Selma::Selector.new(match_element: "img")

Instance Attribute Summary

Attributes inherited from HTMLPipeline::NodeFilter

#context

Attributes inherited from Filter

#context, #result

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from HTMLPipeline::NodeFilter

call, #html, #initialize, #reset!

Methods inherited from Filter

#base_url, #call, call, #has_ancestor?, #initialize, #needs

Constructor Details

This class inherits a constructor from HTMLPipeline::NodeFilter

Class Method Details

.compile_allowlist(domain_list) ⇒ Object 



61
62
63
64
65
66
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 61

def compile_allowlist(domain_list)
  return if domain_list.empty?

  escaped = domain_list.map { |domain| Regexp.escape(domain).gsub("\\*", ".*?") }
  Regexp.new("^(#{escaped.join("|")})$", Regexp::IGNORECASE)
end

.determine_allowlist(proxy_settings) ⇒ Object 



68
69
70
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 68

def determine_allowlist(proxy_settings)
  proxy_settings[:allowlist] || []
end

.transform_context(context, proxy_settings = {}) ⇒ Object

This helps setup the context. It’s not needed if you’re always providing all the necessary keys in the context. One example would be to override this and pull the settings from a set of global application settings.



51
52
53
54
55
56
57
58
59
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 51

def transform_context(context, proxy_settings = {})
  context[:asset_proxy] = proxy_settings[:url] if proxy_settings[:url]
  context[:asset_proxy_secret_key] = proxy_settings[:secret_key] if proxy_settings[:secret_key]

  allowlist = determine_allowlist(proxy_settings)
  context[:asset_proxy_domain_regexp] ||= compile_allowlist(allowlist)

  context
end

Instance Method Details

#asset_host_allowed?(host) ⇒ Boolean

Returns:

  • (Boolean) 


43
44
45
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 43

def asset_host_allowed?(host)
  context[:asset_proxy_domain_regexp] ? context[:asset_proxy_domain_regexp].match?(host) : false
end

#handle_element(element) ⇒ Object 



22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 22

def handle_element(element)
  original_src = element["src"]
  return unless original_src

  begin
    uri = URI.parse(original_src)
  rescue StandardError
    return
  end

  return if uri.host.nil? && !original_src.start_with?("///")
  return if asset_host_allowed?(uri.host)

  element["src"] = asset_proxy_url(original_src)
  element["data-canonical-src"] = original_src
end

#selector ⇒ Object 



18
19
20
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 18

def selector
  SELECTOR
end

#validate ⇒ Object 



39
40
41
 
# File 'lib/html_pipeline/node_filter/asset_proxy_filter.rb', line 39

def validate
  needs(:asset_proxy, :asset_proxy_secret_key)
end